"""
Author: Faye Lee
Date: 2025-04-12 11:49:26
LastEditTime: 2025-05-09 17:07:36
LastEditors: Faye Lee
Description:
FilePath: \pygame_alien\game_functions.py
Halo Baby,欢迎打开新世界的大门!
"""

import sys
import pygame
from time import sleep
from bullet import Bullet
from alien import Alien


def check_keydown_events(event, ai_settings, screen, stats,sb, aliens, ship, bullets):
    """响应按键"""
    if event.key == pygame.K_RIGHT:
        ship.moving_right = True
    elif event.key == pygame.K_LEFT:
        ship.moving_left = True
    elif event.key == pygame.K_UP:
        ship.moving_top = True
    elif event.key == pygame.K_DOWN:
        ship.moving_bottom = True
    elif event.key == pygame.K_SPACE:
        fire_bullet(ai_settings, screen, ship, bullets)
    elif event.key == pygame.K_ESCAPE:
        sys.exit()
    elif event.key == pygame.K_p and not stats.game_active:
        start_game(ai_settings, screen, stats,sb, aliens, bullets, ship)


def check_keyup_events(event, ship):
    """响应松开"""
    if event.key == pygame.K_RIGHT:
        ship.moving_right = False
    elif event.key == pygame.K_LEFT:
        ship.moving_left = False
    elif event.key == pygame.K_UP:
        ship.moving_top = False
    elif event.key == pygame.K_DOWN:
        ship.moving_bottom = False


def check_events(ai_settings, screen, stats,sb, play_button, ship, aliens, bullets):
    """响应按键和鼠标事件"""
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            sys.exit()
        elif event.type == pygame.KEYDOWN:
            check_keydown_events(
                event, ai_settings, screen, stats,sb, aliens, ship, bullets
            )
        elif event.type == pygame.KEYUP:
            check_keyup_events(event, ship)
        elif event.type == pygame.MOUSEBUTTONDOWN:
            mouse_x, mouse_y = pygame.mouse.get_pos()
            check_play_button(
                ai_settings,
                screen,
                stats,
                sb,
                play_button,
                ship,
                aliens,
                bullets,
                mouse_x,
                mouse_y,
            )


def check_play_button(
    ai_settings, screen, stats,sb, play_button, ship, aliens, bullets, mouse_x, mouse_y
):
    """在玩家单击Play按钮时开始新游戏"""
    button_clicked = play_button.rect.collidepoint(mouse_x, mouse_y)
    if button_clicked and not stats.game_active:
        start_game(ai_settings, screen, stats,sb, aliens, bullets, ship)


def start_game(ai_settings, screen, stats,sb, aliens, bullets, ship):
    # 重置游戏统计信息
    stats.reset_stats()
    stats.game_active = True

    # 重置记分牌图像
    sb.prep_score()
    sb.prep_level()
    sb.prep_high_score()
    sb.prep_ships()

    # 清空外星人列表和子弹列表
    aliens.empty()
    bullets.empty()

    # 创建一群新的外星人，并让飞船居中
    create_fleet(ai_settings, screen, ship, aliens)
    ship.center_ship()

    # 隐藏光标
    pygame.mouse.set_visible(False)

    # 重置速度
    ai_settings.initialize_dynamic_settings()


def get_number_rows(ai_settings, ship_height, alien_height):
    """计算屏幕可以容纳多少行外星人"""
    # 除去飞船的高度,剩余的空间
    available_space_y = float(
        ai_settings.screen_height
        - ((1 + ai_settings.alien_space_factor * 6) * alien_height)
        - ship_height
    )
    # 计算可以容纳多少列外星人
    number_rows = int(
        round(
            available_space_y / ((1 + ai_settings.alien_space_factor) * alien_height), 0
        )
    )
    # 计算外星人之间的高度间距
    aliens_space = float(
        (available_space_y - (number_rows * alien_height)) / (number_rows - 1)
    )
    # 返回值
    return {"number": number_rows, "space": aliens_space}


def get_number_alien_x(ai_settings, alien_width):
    """计算每行可容纳多少个外星人,外星人的间距是外星人的宽度的一半"""
    # 除两边的固定空隙外,剩余的宽度
    available_space_x = float(
        ai_settings.screen_width - alien_width * ai_settings.alien_space_factor * 2
    )
    # 外星人的数量
    number_aliens_x = int(
        round(
            available_space_x / ((1 + ai_settings.alien_space_factor) * alien_width), 0
        )
    )
    # 外星人之间的宽度间距
    aliens_space = float(
        (available_space_x - (number_aliens_x * alien_width)) / (number_aliens_x - 1)
    )
    return {"number": number_aliens_x, "space": aliens_space}


def create_alien(
    ai_settings, screen, aliens_space, alien_number, row_space, row_number, aliens
):
    alien = Alien(ai_settings, screen)
    alien_width = alien.rect.width
    alien_height = alien.rect.height
    # 计算每个外星人的位置 x,y分别是横竖坐标轴的距离
    alien.x = (
        alien_width * ai_settings.alien_space_factor
        + (aliens_space + alien_width) * alien_number
    )
    alien.y = (
        alien_height * ai_settings.alien_space_factor
        + (row_space + alien_height) * row_number
    )
    alien.rect.x = alien.x
    alien.rect.y = alien.y
    aliens.add(alien)


def create_fleet(ai_settings, screen, ship, aliens):
    """创建外星人群"""
    # 计算每行可容纳多少个外星人,获取到外星人之间的间隙
    alien = Alien(ai_settings, screen)
    alien_height = alien.rect.height

    alien_col = get_number_alien_x(ai_settings, ai_settings.alien_width)
    alien_rows = get_number_rows(ai_settings, ship.rect.height, alien_height)
    for row_number in range(alien_rows["number"]):
        # 创建一行外星人
        for alien_number in range(alien_col["number"]):
            create_alien(
                ai_settings,
                screen,
                alien_col["space"],
                alien_number,
                alien_rows["space"],
                row_number,
                aliens,
            )


def check_fleet_edges(ai_settings, aliens):
    """有外星人到达边缘时采取相应措施"""
    for alien in aliens.sprites():
        if alien.check_edges():
            change_fleet_direction(ai_settings, aliens)
            break


def change_fleet_direction(ai_settings, aliens):
    """将整群外星人下移，并改变它们的方向"""
    for alien in aliens.sprites():
        alien.rect.y += ai_settings.alien_drop_speed
    ai_settings.fleet_direction *= -1


def ship_hit(ai_settings, stats,sb, screen, ship, aliens, bullets):
    """响应被外星人撞到的飞船"""
    if stats.ships_lives > 0:
        # 将ships_lives 剩余生命值 减1
        stats.ships_lives -= 1
        sb.prep_ships()
        # 清空外星人列表和子弹列表
        aliens.empty()
        bullets.empty()
        # 创建一群新的外星人，并将飞船放到屏幕底端中央
        create_fleet(ai_settings, screen, ship, aliens)
        ship.center_ship()
        # 暂停
        sleep(0.5)
    else:
        stats.game_active = False


def check_aliens_bottom(ai_settings, stats,sb, screen, ship, aliens, bullets):
    """检查是否有外星人到达了屏幕底端"""
    screen_rect = screen.get_rect()
    for alien in aliens.sprites():
        if alien.rect.bottom >= screen_rect.bottom:
            # 处理这种情况的方法同飞船被撞到一样
            ship_hit(ai_settings, stats,sb, screen, ship, aliens, bullets)
            break


def update_aliens(ai_settings, stats, sb,screen, ship, aliens, bullets):
    """检查是否有外星人到达屏幕边缘，然后更新整群外星人的位置"""
    check_fleet_edges(ai_settings, aliens)
    aliens.update()
    # 检测外星人和飞船之间的碰撞
    if pygame.sprite.spritecollideany(ship, aliens):
        ship_hit(ai_settings, stats,sb, screen, ship, aliens, bullets)
    check_aliens_bottom(ai_settings, stats, sb,screen, ship, aliens, bullets)


def fire_bullet(ai_settings, screen, ship, bullets):
    """如果还没有到达限制，就发射一颗子弹"""
    # 创建新子弹，并将其加入到编组bullets中
    if len(bullets) < ai_settings.bullets_allowed:
        new_bullet = Bullet(ai_settings, screen, ship)
        bullets.add(new_bullet)


def update_bullets(ai_settings, screen, stats, sb, ship, aliens, bullets):
    """更新子弹的位置，并删除已消失的子弹"""
    # 更新子弹位置
    bullets.update()
    # 删除已消失的子弹
    for bullet in bullets.copy():
        if bullet.rect.bottom <= 0:
            bullets.remove(bullet)
    check_bullet_alien_collisions(ai_settings, screen, stats, sb, ship, aliens, bullets)


def check_bullet_alien_collisions(
    ai_settings, screen, stats, sb, ship, aliens, bullets
):
    """检查是否有子弹击中了外星人"""
    # 删除已消失的子弹,同时删除外星人,获取到碰撞的子弹和外星人的字典
    collisions = pygame.sprite.groupcollide(bullets, aliens, True, True)
    if collisions:
        for aliens in collisions.values():
            stats.score += ai_settings.alien_points
            sb.prep_score()
            sb.prep_high_score()

    if len(aliens) == 0:
        bullets.empty()
        ai_settings.increase_speed()

        # 提高等级
        stats.level += 1
        sb.prep_level()
        create_fleet(ai_settings, screen, ship, aliens)


def update_screen(ai_settings, screen, stats, sb, ship, aliens, bullets, play_button):
    """更新屏幕上的图像，并切换到新屏幕"""
    # 绘制背景色
    screen.fill(ai_settings.bg_color)
    # 在飞船和外星人后面重绘所有子弹
    for bullet in bullets.sprites():
        bullet.draw_bullet()
    # 绘制飞船
    ship.blitme()
    # 绘制外星人
    aliens.draw(screen)
    # 显示fps
    sb.prep_fps()
    # 显示得分
    sb.show_score()

    # 如果游戏处于非活动状态，就绘制Play按钮
    if not stats.game_active:
        play_button.draw_button()

    # 让最近绘制的屏幕可见
    pygame.display.flip()
